AspectJ:如何将方面库编织到 Java 项目中 [英] AspectJ: How to weave an aspect library into a Java project

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问题描述

我使用 AspectJ 构建小型库(Java 和 Maven).图书馆必须是独立的.库提供方面和注释.库的功能是-执行具有特定注释的方法时调用建议".当我在一个模块中使用所有内容时一切正常，但是当我将库和项目与必须应用建议的类分开时，问题就会出现.我创建了简单的模式.库 B - 我的库(方面和注释)项目 A - 必须应用商业方法的项目有没有可能做到这一点?

I build small library (Java and Maven) - using AspectJ. Library must be independent. Library deliver Aspects and Annotations. Function of library is - "call advice when executed a method with specific annotation". All is ok when I use everything in one module, but problem appers when i separate library and project with classes which advice must be applied. I create simple schema. Library B - my library (aspects and annotations) Project A - project with buisness methods which adivce must be applied Is any posibility to do this?

推荐答案

根据 AspectJ Maven 文档，使用方面库"一章，你需要

  • 将方面库添加为常规,
  • 还在插件部分添加相同的依赖项(没有，因为它已经在步骤1中分配了).
  • add the aspect library as a regular <dependency>,
  • also add the same dependency (without <version> because it is already assigned in step 1) in the plugin <configuration><aspectLibraries> section as an <aspectLibrary>.

这是一个具体的例子:

方面库 POM、标记注释和样例方面:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>de.scrum-master.stackoverflow</groupId>
    <artifactId>aspectj-lib</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <name>AspectJ Library</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.source-target.version>1.8</java.source-target.version>
        <aspectj.version>1.8.7</aspectj.version>
    </properties>

    <build>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.3</version>
                    <configuration>
                        <source>${java.source-target.version}</source>
                        <target>${java.source-target.version}</target>
                        <!-- IMPORTANT -->
                        <useIncrementalCompilation>false</useIncrementalCompilation>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.codehaus.mojo</groupId>
                    <artifactId>aspectj-maven-plugin</artifactId>
                    <version>1.7</version>
                    <configuration>
                        <!--<showWeaveInfo>true</showWeaveInfo> -->
                        <source>${java.source-target.version}</source>
                        <target>${java.source-target.version}</target>
                        <Xlint>ignore</Xlint>
                        <complianceLevel>${java.source-target.version}</complianceLevel>
                        <encoding>${project.build.sourceEncoding}</encoding>
                        <!--<verbose>true</verbose> -->
                        <!--<warn>constructorName,packageDefaultMethod,deprecation,maskedCatchBlocks,unusedLocals,unusedArguments,unusedImport</warn> -->
                    </configuration>
                    <executions>
                        <execution>
                            <!-- IMPORTANT -->
                            <phase>process-sources</phase>
                            <goals>
                                <goal>compile</goal>
                                <goal>test-compile</goal>
                            </goals>
                        </execution>
                    </executions>
                    <dependencies>
                        <dependency>
                            <groupId>org.aspectj</groupId>
                            <artifactId>aspectjtools</artifactId>
                            <version>${aspectj.version}</version>
                        </dependency>
                    </dependencies>
                </plugin>
            </plugins>
        </pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>aspectj-maven-plugin</artifactId>
            </plugin>
            <!--
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
            </plugin>
            -->
        </plugins>
    </build>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.aspectj</groupId>
                <artifactId>aspectjrt</artifactId>
                <version>${aspectj.version}</version>
                <scope>runtime</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
        </dependency>
    </dependencies>

    <organization>
        <name>Scrum-Master.de - Agile Project Management</name>
        <url>http://scrum-master.de</url>
    </organization>

</project>


package de.scrum_master.aspect;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface Marker {}


package de.scrum_master.aspect;

public aspect MyAspect {
    before() : execution(* *(..)) && @annotation(Marker) {
        System.out.println(thisJoinPoint);
    }
}

现在在方面库项目上运行 mvn clean install 以便将依赖项安装到您的本地 Maven 存储库中.

Now run mvn clean install on the aspect library project so as to install the dependency into your local Maven repo.

Java 应用程序 POM 和示例应用程序:

顺便说一下，在 POM 中我还添加了两个可选插件:

By the way, in the POM I have also added two optional plugins:

  • One-JAR 插件将您的应用程序与所有依赖项(例如方面库和 AspectJ 运行时)打包到一个工件中，这里是 target/java-app-0.0.1-SNAPSHOT.one-jar.jar.您可以通过 java -jar target/java-app-0.0.1-SNAPSHOT.one-jar.jar 运行您的应用程序.
  • Exec Maven 插件非常有用，如果您想通过 mvn clean install exec:java 从命令行轻松测试您的应用程序.
  • One-JAR plugin packages your application with all dependencies (e.g. aspect library and AspectJ runtime) into one artifact, here target/java-app-0.0.1-SNAPSHOT.one-jar.jar. You can just run your application via java -jar target/java-app-0.0.1-SNAPSHOT.one-jar.jar.
  • Exec Maven plugin is useful if you easily want to test your application from the command line via mvn clean install exec:java.

这两个只是为了方便，不喜欢的可以不用.

These two are only for convenience, you do not need them if you dislike them.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>de.scrum-master.stackoverflow</groupId>
    <artifactId>java-app</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <name>Java Application</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.source-target.version>1.8</java.source-target.version>
        <aspectj.version>1.8.7</aspectj.version>
        <main-class>de.scrum_master.app.Application</main-class>
    </properties>

    <build>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.3</version>
                    <configuration>
                        <source>${java.source-target.version}</source>
                        <target>${java.source-target.version}</target>
                        <!-- IMPORTANT -->
                        <useIncrementalCompilation>false</useIncrementalCompilation>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.codehaus.mojo</groupId>
                    <artifactId>aspectj-maven-plugin</artifactId>
                    <version>1.7</version>
                    <configuration>
                        <!--<showWeaveInfo>true</showWeaveInfo> -->
                        <source>${java.source-target.version}</source>
                        <target>${java.source-target.version}</target>
                        <Xlint>ignore</Xlint>
                        <complianceLevel>${java.source-target.version}</complianceLevel>
                        <encoding>${project.build.sourceEncoding}</encoding>
                        <!--<verbose>true</verbose> -->
                        <!--<warn>constructorName,packageDefaultMethod,deprecation,maskedCatchBlocks,unusedLocals,unusedArguments,unusedImport</warn> -->
                        <aspectLibraries>
                            <aspectLibrary>
                                <groupId>de.scrum-master.stackoverflow</groupId>
                                <artifactId>aspectj-lib</artifactId>
                            </aspectLibrary>
                        </aspectLibraries>
                    </configuration>
                    <executions>
                        <execution>
                            <!-- IMPORTANT -->
                            <phase>process-sources</phase>
                            <goals>
                                <goal>compile</goal>
                                <goal>test-compile</goal>
                            </goals>
                        </execution>
                    </executions>
                    <dependencies>
                        <dependency>
                            <groupId>org.aspectj</groupId>
                            <artifactId>aspectjtools</artifactId>
                            <version>${aspectj.version}</version>
                        </dependency>
                    </dependencies>
                </plugin>
                <plugin>
                    <groupId>org.codehaus.mojo</groupId>
                    <artifactId>exec-maven-plugin</artifactId>
                    <version>1.4.0</version>
                    <configuration>
                        <mainClass>${main-class}</mainClass>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.dstovall</groupId>
                    <artifactId>onejar-maven-plugin</artifactId>
                    <version>1.4.4</version>
                    <executions>
                        <execution>
                            <goals>
                                <goal>one-jar</goal>
                            </goals>
                        </execution>
                    </executions>
                    <configuration>
                        <onejarVersion>0.96</onejarVersion>
                        <mainClass>${main-class}</mainClass>
                        <attachToBuild>true</attachToBuild>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>aspectj-maven-plugin</artifactId>
            </plugin>
            <!--
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
            </plugin>
            -->
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <configuration>
                    <mainClass>${main-class}</mainClass>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.dstovall</groupId>
                <artifactId>onejar-maven-plugin</artifactId>
                <configuration>
                    <mainClass>${main-class}</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <pluginRepositories>
        <pluginRepository>
            <id>OneJAR googlecode.com</id>
            <url>http://onejar-maven-plugin.googlecode.com/svn/mavenrepo</url>
        </pluginRepository>
    </pluginRepositories>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.aspectj</groupId>
                <artifactId>aspectjrt</artifactId>
                <version>${aspectj.version}</version>
                <scope>runtime</scope>
            </dependency>
            <dependency>
                <groupId>de.scrum-master.stackoverflow</groupId>
                <artifactId>aspectj-lib</artifactId>
                <version>0.0.1-SNAPSHOT</version>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
        </dependency>
            <dependency>
                <groupId>de.scrum-master.stackoverflow</groupId>
                <artifactId>aspectj-lib</artifactId>
            </dependency>
    </dependencies>

    <organization>
        <name>Scrum-Master.de - Agile Project Management</name>
        <url>http://scrum-master.de</url>
    </organization>

</project>

这个小驱动程序演示了您现在可以使用 @Marker 注释方法，在这种情况下只有 foo 和 zot，但不能使用 <代码>条形:

This little driver application demonstrates that you can now annotate methods with @Marker, in this case only foo and zot, but not bar:

package de.scrum_master.app;

import de.scrum_master.aspect.Marker;

public class Application {
    @Marker
    public static void foo() {}

    public static void bar() {}

    @Marker
    public static void zot() {}

    public static void main(String[] args) {
        foo();
        bar();
        zot();
    }
}

控制台日志:

java -jar target/java-app-0.0.1-SNAPSHOT.one-jar.jar

execution(void de.scrum_master.app.Application.foo())
execution(void de.scrum_master.app.Application.zot())

这篇关于AspectJ:如何将方面库编织到 Java 项目中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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